This invention relates to a wireless sensor and communications system, and more particularly, a wireless integrated microsystem for wirelessly transmitting environmental data at radio frequencies.
The gathering, distribution, and dissemination of data is an integral part of virtually every industrial process. A common means for performing data gathering and analysis is provided through use of data sensors. Data sensors provide versatile functionality to nearly every major industry, providing status information, allowing for the performance of various control functions, and often defining the means by which various elements communicate. Moreover, most electronic systems in use today employ the use of data sensors as an essential building block, often providing the backbone for overall system performance.
Major advancements in circuit fabrication techniques, as well as recent growth and interest in microelectromechanical systems (MEMS) and nanotechnology, have significantly increased the potential for sensor implementation in system architectures. Developers have been finding new ways to incorporate data sensors to increase functional flexibility by implementing sensor technology with communication systems, allowing for wireless and remote sensing capabilities. Until recently, many system architectures have performed multiple functions, such as sensing and communication, but have been limited to split architectures, whereby sensing and communication, for example, were performed separately. This is due, in a large part in the sensitivity in communications equipment, especially wireless and radio frequency elements, to interference and power limitations, as well as fabrication and process tolerance limitations. However, with recent advancements in batch fabrication process technology, as well as the ever-increasing desire to realize system on chip (SoC) architectures, the limitations to split chip circuit design are slowly being resolved. In fact, Wireless Integrated MicroSystems (WIMS) is a science wholly dedicated to the techniques of developing integrated information-gathering circuits, which are capable of interfacing electronics with the non-electronic world. Thus, with the development of SoC technology, there has been a natural evolution of traditional integrated circuit sensing devices composed of only electronic devices, to MEMS and microsystem sensors which utilize mechanical transducers in conjunction with electrical components. Some measures have been employed in the art to address the need for environmentally sensitive sensors that can communicate data wirelessly.
U.S. Pat. No. 6,546,268 to Ishikawa describes a glucose sensor based on ball integrated circuit technology mounted with sensor media operable for sensing biochemical molecules. The ball semiconductor sensor (100) has circuitry comprising an RF antenna coil (118), and RF rectifier-smoother (121), an RF amplifier (122), and control logic (124). The sensor communicates to a pump actuator or to an externally located radio frequency transmitter/receiver. However, sensing function and communication function are two separate, distinct functions.
U.S. Pat. No. 6,452,499 to Runge describes an atmospheric precipitation sensor system that communicates sensor data to a receiving unit. An environmental sensor (2) is connected to a transmitter control circuit (4). Transmitter control circuit (4) is connected to a transmitter (6), for transmission of data signal wirelessly to a receiver module, which controls an irrigation system. In the system described in the Runge patent, sensing function and transmitting functions are two separate functions.
Another problem in the existing art is that of power consumption due, in a large part, to the split sense and transmit functional architecture. For many of these systems, the external communication system limits the applicability of the sensor system, due to the inefficiency of the split architecture approach. As a result, there is an unfulfilled need in the current art to combine the sensor as part of the radio frequency communication circuit to increase the efficiency, thereby increasing the applicability of the sensor communication platform.
A heretofore-unfilled need exists for a sensor element that is integrated as part of the communication system, whereby said sensor element provides functionality within the communication system based on the sensed condition. This sensed condition causes the sensor element to interact with the communication system to modify the characteristics of the output signal of the communication system. Thus, the sensor element is no longer a separate element from the communication system, but an integrated device, which results in the fusion of the sensor and communication functions into one integrated single function. Another need exists for a sensor system integrated as a radio frequency integrated circuit element for providing an output signal indicative of a sensed condition, when exposed to environmental stimuli.
In addition, manufacturers currently need to provide some interactive means coupling the output of the sensor to the transmitter circuitry, requiring the need for control systems and external interconnects, thereby requiring additional post-process manufacturing. The required control circuitry and external interconnects of split function architectures increase the overall power consumption which, in nearly all applications, is an important factor in limiting overall system functionality.
Therefore, it is to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed.
However, in view of the prior art at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.